duuyguyiilmaz · Sep 1, 2026 · Sep 1, 2026
diff --git a/README.md b/README.md
@@ -322,7 +322,7 @@ emulator on API 24+.
 ./gradlew testDebugUnitTest
 ```
 
-114 JVM tests, no emulator and no network. They cover the layers where a bug would be
+129 JVM tests, no emulator and no network. They cover the layers where a bug would be
 invisible rather than loud: the scoring arithmetic, the decision logic in every
 ViewModel, the list diffing that decides which rows get redrawn, and — for the feature
 the app is built around — what the screen actually shows.
@@ -336,6 +336,8 @@ the app is built around — what the screen actually shows.
 | `EditNoteViewModelTest` | Ownership and session handling on load and save. |
 | `ProfileViewModelTest` | Total points summed from the user's own notes, and note deletion. |
 | `LoginViewModelTest`, `RegisterViewModelTest` | State transitions, and which of registration's two steps — auth account or profile document — failed. |
+| `AuthErrorMessagesTest` | That each Firebase auth error code reaches its own Turkish message rather than the catch-all. The mapping used to match on Firebase's English error *sentence*; those strings are not API, they changed, and every failure quietly collapsed into "Tekrar deneyin." with no test to notice. `ERROR_INVALID_CREDENTIAL` is the sharp case — with email enumeration protection on, it is what both a wrong password and an unknown account now return. |
+| `PasswordToggleTest` | That the password field starts masked and its toggle icon reports state, not action: unchecked (crossed-out eye) while hidden, checked (open eye) while visible. The icon is a custom selector wired through `endIconDrawable`, so dropping that one attribute leaves a working button with the inverted icon — invisible to every other test. |
 | `LeaderboardViewModelTest` | Empty vs. content, and the department scoping: which department the ranking is asked for, and the three cases — no session, no profile, blank department — where the query must not be built at all. |
 | `MainViewModelTest`, `UploaderNameTest` | Session routing, and the uploader-name masking shared by three screens. |
 | `PostAdapterTest`, `LeaderboardAdapterTest` | Which rows a `DiffUtil` pass marks as changed. The leaderboard case is the sharp one: a note's medal depends on its rank, so a note that swapped places without changing must still be rebound, or the gold medal stays on the row it left. |
@@ -377,7 +379,7 @@ test through a `FragmentFactory`, which is what lets the existing repository fak
 a real screen.
 
 The inverted-gate mutation above is not hypothetical: applying it turns five of these
-six tests red and leaves all 96 other tests green.
+six tests red and leaves every other test in the suite green.
 
 ### Rules tests
 

diff --git a/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/AuthErrorMessages.kt b/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/AuthErrorMessages.kt
@@ -0,0 +1,49 @@
+package duygu.yilmaz.campusnote.ui.auth
+
+import androidx.annotation.StringRes
+import com.google.firebase.FirebaseNetworkException
+import com.google.firebase.auth.FirebaseAuthException
+import duygu.yilmaz.campusnote.R
+
+/**
+ * Giriş ve kayıt hatalarını kullanıcıya gösterilecek Türkçe metne çevirir.
+ *
+ * Eskiden bu eşleme Firebase'in İngilizce hata *cümlesinde* `contains` araması
+ * yapıyordu ("password is invalid", "no user record"). O cümleler API'nin bir parçası
+ * değil; SDK sürümleriyle değiştiler ve eşleşme sessizce bozuldu — her hata "Tekrar
+ * deneyin."e düştü, yani kullanıcı şifresini mi yanlış yazdığını yoksa internetinin mi
+ * gittiğini anlayamadı. [FirebaseAuthException.errorCode] ise sabit bir sözleşme.
+ */
+enum class AuthAction { SIGN_IN, REGISTER }
+
+fun authErrorMessage(exception: Throwable, action: AuthAction): Int = when (exception) {
+    is FirebaseNetworkException -> R.string.error_network
+    is FirebaseAuthException -> messageForAuthErrorCode(exception.errorCode, action)
+    else -> messageForAuthErrorCode(null, action)
+}
+
+/**
+ * Kodu metne çeviren saf fonksiyon — Firebase tipine ihtiyaç duymadığı için JVM
+ * testinden doğrudan çağrılabiliyor.
+ *
+ * Bilinmeyen kod, eylemin kendi genel mesajına düşer: kayıt ile giriş aynı cümleyi
+ * paylaşamaz, "Giriş başarısız" kayıt ekranında yanlış olur.
+ */
+@StringRes
+fun messageForAuthErrorCode(errorCode: String?, action: AuthAction): Int = when (errorCode) {
+    "ERROR_INVALID_EMAIL" -> R.string.error_invalid_email_format
+    "ERROR_EMAIL_ALREADY_IN_USE" -> R.string.register_error_email_in_use
+    "ERROR_WEAK_PASSWORD" -> R.string.register_error_weak_password
+    "ERROR_USER_NOT_FOUND" -> R.string.login_error_user_not_found
+    "ERROR_WRONG_PASSWORD" -> R.string.login_error_wrong_password
+    // Güncel Firebase, yanlış şifre ile olmayan hesabı bu tek kodda birleştiriyor.
+    "ERROR_INVALID_CREDENTIAL" -> R.string.login_error_invalid_credentials
+    "ERROR_USER_DISABLED" -> R.string.error_user_disabled
+    "ERROR_TOO_MANY_REQUESTS" -> R.string.error_too_many_requests
+    "ERROR_OPERATION_NOT_ALLOWED" -> R.string.error_operation_not_allowed
+    "ERROR_NETWORK_REQUEST_FAILED" -> R.string.error_network
+    else -> when (action) {
+        AuthAction.SIGN_IN -> R.string.login_error_generic
+        AuthAction.REGISTER -> R.string.register_error_generic
+    }
+}
diff --git a/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/LoginActivity.kt b/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/LoginActivity.kt
@@ -1,7 +1,6 @@
 package duygu.yilmaz.campusnote.ui.auth
 
 import android.content.Intent
-import android.content.SharedPreferences
 import android.os.Bundle
 import android.view.View
 import android.widget.Toast
@@ -16,21 +15,28 @@ class LoginActivity : AppCompatActivity() {
     private val viewModel: LoginViewModel by viewModels()
     private lateinit var binding: ActivityLoginBinding
 
+    /**
+     * Oturum, kullanıcı Profil'den çıkış yapana kadar açık kalır.
+     *
+     * Eskiden burada bir "Oturumu açık tut" kutusu vardı ve atlama yalnızca kutu
+     * işaretliyse yapılıyordu. Firebase oturumu zaten diske yazdığı için kutu
+     * işaretsizken kullanıcı hâlâ giriş yapmış oluyordu — uygulama sadece bunu yok
+     * sayıp formu gösteriyordu. Sonuç: uygulamadan yanlışlıkla çıkan biri her
+     * açılışta şifresini yeniden yazmak zorunda kalıyordu, üstelik "çıkış yapmış"
+     * da değildi. Kutu kaldırıldı; çıkış tek yerden, Profil'deki düğmeden yapılıyor.
+     */
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        val prefs = getSharedPreferences(PREFS_NAME, MODE_PRIVATE)
-
-        val rememberMe = prefs.getBoolean(KEY_REMEMBER_ME, false)
-        if (rememberMe && viewModel.hasAuthenticatedUser()) {
+        if (viewModel.hasAuthenticatedUser()) {
             goToMainActivity()
             return
         }
 
         binding = ActivityLoginBinding.inflate(layoutInflater)
         setContentView(binding.root)
 
-        observeAuthState(prefs)
+        observeAuthState()
         setupClickListeners()
         animateViews()
     }
@@ -50,14 +56,13 @@ class LoginActivity : AppCompatActivity() {
         }
     }
 
-    private fun observeAuthState(prefs: SharedPreferences) {
+    private fun observeAuthState() {
         viewModel.uiState.observe(this) { state ->
             when (state) {
                 AuthUiState.Idle -> showLoading(false)
                 AuthUiState.Loading -> showLoading(true)
                 AuthUiState.Success -> {
                     viewModel.resetState()
-                    prefs.edit().putBoolean(KEY_REMEMBER_ME, binding.cbRememberMe.isChecked).apply()
                     showLoading(false)
                     Toast.makeText(this, R.string.login_welcome, Toast.LENGTH_SHORT).show()
                     goToMainActivity()
@@ -155,18 +160,7 @@ class LoginActivity : AppCompatActivity() {
 
     /** Firebase hata metinleri yerelleştirilmemiş geliyor; kullanıcıya Türkçesini gösteriyoruz. */
     private fun showFirebaseError(e: Exception) {
-        val messageId = when {
-            e.message?.contains("no user record") == true ->
-                R.string.login_error_user_not_found
-            e.message?.contains("password is invalid") == true ->
-                R.string.login_error_wrong_password
-            e.message?.contains("badly formatted") == true ->
-                R.string.error_invalid_email_format
-            e.message?.contains("network") == true ->
-                R.string.error_network
-            else -> R.string.login_error_generic
-        }
-        Toast.makeText(this, messageId, Toast.LENGTH_LONG).show()
+        Toast.makeText(this, authErrorMessage(e, AuthAction.SIGN_IN), Toast.LENGTH_LONG).show()
     }
 
     private fun goToMainActivity() {
@@ -175,8 +169,6 @@ class LoginActivity : AppCompatActivity() {
     }
 
     private companion object {
-        const val PREFS_NAME = "campusnote_prefs"
-        const val KEY_REMEMBER_ME = "remember_me"
         const val MIN_PASSWORD_LENGTH = 6
     }
 }
diff --git a/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/RegisterActivity.kt b/app/src/main/java/duygu/yilmaz/campusnote/ui/auth/RegisterActivity.kt
@@ -187,18 +187,7 @@ class RegisterActivity : AppCompatActivity() {
 
     /** Firebase hata metinleri yerelleştirilmemiş geliyor; kullanıcıya Türkçesini gösteriyoruz. */
     private fun showFirebaseError(e: Exception) {
-        val messageId = when {
-            e.message?.contains("email address is already") == true ->
-                R.string.register_error_email_in_use
-            e.message?.contains("badly formatted") == true ->
-                R.string.error_invalid_email_format
-            e.message?.contains("weak password") == true ->
-                R.string.register_error_weak_password
-            e.message?.contains("network") == true ->
-                R.string.error_network
-            else -> R.string.register_error_generic
-        }
-        Toast.makeText(this, messageId, Toast.LENGTH_LONG).show()
+        Toast.makeText(this, authErrorMessage(e, AuthAction.REGISTER), Toast.LENGTH_LONG).show()
     }
 
     private fun goToMainActivity() {

diff --git a/app/src/main/java/duygu/yilmaz/campusnote/ui/leaderboard/LeaderboardFragment.kt b/app/src/main/java/duygu/yilmaz/campusnote/ui/leaderboard/LeaderboardFragment.kt
@@ -19,6 +19,17 @@ class LeaderboardFragment : Fragment() {
 
     private lateinit var adapter: LeaderboardAdapter
 
+    /**
+     * Ekranda duran hata snackbar'ı.
+     *
+     * Referans tutuluyor çünkü snackbar bu fragment'ın değil, [MainActivity]'nin
+     * CoordinatorLayout'una bağlanıyor — sekme değiştirmek fragment'ı yok etse de
+     * snackbar'ı yok etmiyordu. [Snackbar.LENGTH_INDEFINITE] ile birleşince sıralama
+     * hatası kullanıcıyı yükleme ve profil sekmelerine kadar takip ediyor, hiç
+     * kapanmıyordu; index eksikken "Tekrar dene" de her seferinde yenisini açıyordu.
+     */
+    private var errorSnackbar: Snackbar? = null
+
     private val viewModel: LeaderboardViewModel by lazy {
         ViewModelProvider(this)[LeaderboardViewModel::class.java]
     }
@@ -56,6 +67,8 @@ class LeaderboardFragment : Fragment() {
     }
 
     override fun onStop() {
+        // Dinleyiciyle birlikte hata mesajı da gitmeli: ikisi de bu ekrana ait.
+        dismissError()
         viewModel.stopLeaderboard()
         super.onStop()
     }
@@ -106,12 +119,15 @@ class LeaderboardFragment : Fragment() {
             }
 
             LeaderboardUiState.Empty -> {
+                dismissError()
                 adapter.refresh(emptyList())
                 binding.rvLeaderboard.visibility = View.GONE
                 binding.layoutEmpty.visibility = View.VISIBLE
             }
 
             is LeaderboardUiState.Content -> {
+                // Yeniden deneme tuttuğunda eski hata kendiliğinden kapanmalı.
+                dismissError()
                 adapter.refresh(state.entries)
                 binding.rvLeaderboard.visibility = View.VISIBLE
                 binding.layoutEmpty.visibility = View.GONE
@@ -148,9 +164,17 @@ class LeaderboardFragment : Fragment() {
      * çizilir ve kapatılana kadar sekme değiştirmeyi engellerdi.
      */
     private fun showRetryableError(message: String) {
-        Snackbar.make(binding.root, message, Snackbar.LENGTH_INDEFINITE)
+        // Üst üste binen snackbar'lar yerine tek bir tane: hata her tekrar denemede
+        // yeniden geliyor, biriktirmenin anlamı yok.
+        dismissError()
+        errorSnackbar = Snackbar.make(binding.root, message, Snackbar.LENGTH_INDEFINITE)
             .setAnchorView(R.id.bottomNav)
             .setAction(R.string.action_retry) { viewModel.startLeaderboard() }
-            .show()
+            .also { it.show() }
+    }
+
+    private fun dismissError() {
+        errorSnackbar?.dismiss()
+        errorSnackbar = null
     }
 }
diff --git a/app/src/main/java/duygu/yilmaz/campusnote/ui/profile/ProfileFragment.kt b/app/src/main/java/duygu/yilmaz/campusnote/ui/profile/ProfileFragment.kt
@@ -27,6 +27,14 @@ class ProfileFragment : Fragment() {
 
     private lateinit var myNotesAdapter: PostAdapter
 
+    /**
+     * Ekranda duran hata snackbar'ı; sebebi için bkz. [showRetryableError].
+     *
+     * Snackbar bu fragment'ın değil, [MainActivity]'nin CoordinatorLayout'una
+     * bağlanıyor, dolayısıyla sekme değiştirmek onu kapatmıyor.
+     */
+    private var errorSnackbar: Snackbar? = null
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
@@ -132,6 +140,8 @@ class ProfileFragment : Fragment() {
     }
 
     override fun onStop() {
+        // Dinleyiciyle birlikte hata mesajı da gitmeli: ikisi de bu ekrana ait.
+        dismissError()
         viewModel.stopProfile()
         super.onStop()
     }
@@ -147,6 +157,8 @@ class ProfileFragment : Fragment() {
             }
 
             is ProfileUiState.Content -> {
+                // Yeniden deneme tuttuğunda eski hata kendiliğinden kapanmalı.
+                dismissError()
                 binding.tvEmail.text = state.email
                 binding.tvDepartment.text = state.department
                 binding.tvAvatar.text = state.email.firstOrNull()?.uppercaseChar()?.toString()
@@ -191,10 +203,16 @@ class ProfileFragment : Fragment() {
      * çizilir ve kapatılana kadar sekme değiştirmeyi engellerdi.
      */
     private fun showRetryableError(message: String) {
-        Snackbar.make(binding.root, message, Snackbar.LENGTH_INDEFINITE)
+        dismissError()
+        errorSnackbar = Snackbar.make(binding.root, message, Snackbar.LENGTH_INDEFINITE)
             .setAnchorView(R.id.bottomNav)
             .setAction(R.string.action_retry) { viewModel.startProfile() }
-            .show()
+            .also { it.show() }
+    }
+
+    private fun dismissError() {
+        errorSnackbar?.dismiss()
+        errorSnackbar = null
     }
 
     private fun renderActionState(state: ProfileActionState) {

diff --git a/app/src/main/res/drawable/ic_password_toggle.xml b/app/src/main/res/drawable/ic_password_toggle.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    Şifre görünürlük düğmesinin ikonu.
+
+    Material'in varsayılanı *eylemi* gösterir: şifre gizliyken açık göz ("göstermek
+    için bas"). Bu uygulama *durumu* gösteriyor — gizliyken üstü çizili göz, görünürken
+    açık göz — çünkü kullanıcılar ikonu "şu an ne olduğu" olarak okuyor.
+
+    `state_checked`, TextInputLayout'un password_toggle end icon'unda "şifre görünür"
+    demek; işaretsiz hâli gizli şifredir.
+-->
+<selector xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:state_checked="true" android:drawable="@drawable/ic_visibility"/>
+    <item android:drawable="@drawable/ic_visibility_off"/>
+</selector>
diff --git a/app/src/main/res/drawable/ic_visibility.xml b/app/src/main/res/drawable/ic_visibility.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@color/white"
+        android:pathData="M12,4.5C7,4.5 2.73,7.61 1,12c1.73,4.39 6,7.5 11,7.5s9.27,-3.11 11,-7.5c-1.73,-4.39 -6,-7.5 -11,-7.5zM12,17c-2.76,0 -5,-2.24 -5,-5s2.24,-5 5,-5s5,2.24 5,5s-2.24,5 -5,5zM12,9c-1.66,0 -3,1.34 -3,3s1.34,3 3,3s3,-1.34 3,-3s-1.34,-3 -3,-3z"/>
+</vector>
diff --git a/app/src/main/res/drawable/ic_visibility_off.xml b/app/src/main/res/drawable/ic_visibility_off.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@color/white"
+        android:pathData="M12,7c2.76,0 5,2.24 5,5c0,0.65 -0.13,1.26 -0.36,1.83l2.92,2.92c1.51,-1.26 2.7,-2.89 3.43,-4.75c-1.73,-4.39 -6,-7.5 -11,-7.5c-1.4,0 -2.74,0.25 -3.98,0.7l2.16,2.16C10.74,7.13 11.35,7 12,7zM2,4.27l2.28,2.28l0.46,0.46C3.08,8.3 1.78,10.02 1,12c1.73,4.39 6,7.5 11,7.5c1.55,0 3.03,-0.3 4.38,-0.84l0.42,0.42L19.73,22L21,20.73L3.27,3L2,4.27zM7.53,9.8l1.55,1.55c-0.05,0.21 -0.08,0.43 -0.08,0.65c0,1.66 1.34,3 3,3c0.22,0 0.44,-0.03 0.65,-0.08l1.55,1.55c-0.67,0.33 -1.41,0.53 -2.2,0.53c-2.76,0 -5,-2.24 -5,-5c0,-0.79 0.2,-1.53 0.53,-2.2zM11.84,9.02l3.15,3.15l0.02,-0.16c0,-1.66 -1.34,-3 -3,-3L11.84,9.02z"/>
+</vector>
diff --git a/app/src/main/res/layout/activity_login.xml b/app/src/main/res/layout/activity_login.xml
@@ -104,8 +104,9 @@
                 android:id="@+id/tilPassword"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                app:passwordToggleEnabled="true"
-                app:passwordToggleTint="@color/input_text"
+                app:endIconMode="password_toggle"
+                app:endIconDrawable="@drawable/ic_password_toggle"
+                app:endIconTint="@color/input_text"
                 style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                 app:startIconDrawable="@drawable/ic_lock"
                 app:startIconTint="@color/soft_orange"
@@ -138,16 +139,6 @@
                     android:fontFamily="@font/poppins_regular"/>
             </com.google.android.material.textfield.TextInputLayout>
 
-            <CheckBox
-                android:id="@+id/cbRememberMe"
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="@string/login_keep_signed_in"
-                android:textColor="@color/white"
-                android:textSize="13sp"
-                android:fontFamily="@font/poppins_regular"
-                android:buttonTint="@color/soft_orange"
-                android:layout_marginTop="8dp"/>
         </LinearLayout>
 
         <ProgressBar

diff --git a/app/src/main/res/layout/activity_register.xml b/app/src/main/res/layout/activity_register.xml
@@ -104,8 +104,9 @@
                 android:id="@+id/tilPassword"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
-                app:passwordToggleEnabled="true"
-                app:passwordToggleTint="@color/input_text"
+                app:endIconMode="password_toggle"
+                app:endIconDrawable="@drawable/ic_password_toggle"
+                app:endIconTint="@color/input_text"
                 style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
                 app:startIconDrawable="@drawable/ic_lock"
                 app:startIconTint="@color/soft_orange"